The midfielder left Chelsea for Toro on Monday's transfer deadline day.
Casadei told La Gazzetta dello Sport: "I couldn't wait to return to Italy. I had been trying for a long time, but I was hindered. The years in England were very useful to me.
"From day one, Torino showed a lot of confidence, starting with (president Urbano) Cairo. The negotiations went on for quite a while. And the president made a great financial effort, I'm sure that Torino is the perfect choice for me.
The midfielder said of Toro coach Paolo Vanoli: "I had a nice chat with him on Monday. The coach is one of the reasons why I wanted to come here. I knew him from (Antonio) Conte's time at Inter, I was a kid in the Primavera."
He added, "I live a quiet life, football represents more than 80% of my life. Now I want to see a few houses and settle down as soon as possible.
"I learned a lot from (Chelsea manager Enzo) Maresca, he taught me a different way of seeing football. I see myself in (Sergej) Milinkovic-Savic for physical and technical characteristics, for me he was a great inspiration. And the national team is my goal, 100%. I dream of winning a World Cup in Azzurri."